Method of protecting surfaces by coating with imide-ester derivatives of ethene-maleic anhydride copolymers

ABSTRACT

A method of protecting surfaces by coating the surfaces with imide-ester derivatives of ethene - maleic anhydride copolymers which are prepared in a two step reaction. These derivatives are useful as adhesives and protective coatings.

nited States Patent ['1 Morduchowitz [111 3,810,276 1451 May 14,1974

[ METHOD OF PROTECTING SURFACES BY COATING WITH IMIDE-ESTER DERIVATIVESOF ETI-IENE-MALEIC ANHYDRIDE COPOLYMERS [75] Inventor: Abraham Morduchowitz, Monsey,

[73] Assignee: Texaco Inc., New York, NY.

[22] Filed: Dec. 29, 1970 [21] App]. No.: 102,539

[52] 11.8. C1. 117/132 B, 117/124 E, 117/145, 117/148, 117/155 UA,117/161 UN, 117/161 UC, 117/161 K, 260/785 B, 260/785 T [51] Int. Cl844d 1/09 [58] Field'of Search.. 117/161 K, 161 UN, 161 UC,

117/132 B, 145,155 UA,124 E, 148; 260/785 B, 78.5 T

[56] 7 References Cited UNITED STATES PATENTS 2,977,334 3/1961 Zopf eta1 260/785 T Primary Examiner-William D. Martin AssistantExaminer-Janyce A. Bell Attorney, Agent, or Firm--Thomas H. Whaley; CarlG. Ries 5 7] ABSTRACT 5 Claims, No Drawings METHOD OF PROTECTINGSURFACES BY COATING WITH IMIDE-ESTER DERIVATIVES OF ETHENlE-MALEIC ANHYDRIDE COPOLYMERS BACKGROUND OF THE INVENTION This invention relates toimide-ester copolymer derivatives, their preparation and use. Inparticular, this invention relates to imide-ester copolymers of ethenemaleic anhydride copolymers, their preparation and use.

Polymers and copolymers have a variety of uses, including use asprotective coatings and as adhesives. Epoxy resins, for example, haveexcellent adhesion properties producing a strong bond but the layer-ofepoxy resin is not clear and transparent which would be a usefulproperty, particularly if the surface or surfaces to which it isadhering is transparent.

Resins which are useful as protective coatings and adhesives,particularly those producing a transparent bond are most desirable andit is the purpose of this invention to provide such a material.

SUMMARY or THE INVENTION Broadly, our invention is directed toimide-ester derivatives of ethene-maleic anhydride copolymers, theirpreparation and use as protective coatings and adhesives. In a two stepreaction process, a 1:1 ethenemaleic anhydride linear copolymer isreacted with an aliphatic alcohol and then further reacted,catalytically, with an amino compound. These imide-ester derivativesfind utility as protective coatings and form a transparent bond whenutilized as an adhesive.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Broadly, l have found that animide-ester copolymer derivative prepared in a two step reaction processhas particular utility as a protective coating and an adhesive.

The process for preparing these derivatives comprises:

a.'reacting together under refluxing conditions a 1:1

linear copolymer of ethene and maleic anhydride having a molecularweight between about 10,000 .and 25,000 dissolved in a hydrocarbonsolvent and an alcohol selected from the group consisting of C saturatedaliphatic alcohols, C unsaturated aliphatic alcohols and mixturesthereof,

b. adding to the reaction mixture of step (a) an amino compound selectedfrom the group consisting of N -(C )alkyl-l ,3-diaminopropane, N-(C)alkenyl-l,3-diaminopropane, C alkylamine, C alkenylamine and mixturesthereof, and a catalyst comprising a strong organo-inorganic acid,

c. reacting under refluxing conditions the reaction mixture of step (b),and

d. recovering from the reaction mixture, an imideester derivative of theethene-maleic anhydride copolymer.

In accordance with this invention the copolymer derivatives are preparedin a two step reaction wherein the active ingredients comprise anethene-maleic anhydride copolymer, an alcohol and an amino compound. Theuseful copolymers are linear copolymers of ethene and maleic anhydridehaving an average molecular weight between about 10,000 and 25,000,particularly an average molecular weight between about 15,000 and20,000. These copolymers have the following recurring copolymeric unitstructure:

When referring herein to a mole of the copolymer, I mean a mole" or theformula weight of this recurring copolymeric unit.

The alcohols which I find useful are the C saturated aliphatic alcohols,the C unsaturated aliphatic alcohols and mixtures thereof, particularlydodecanol, tetradecanol, hexadecanol and octadecanol, with l-dodecanolbeing particularly preferred.

The useful amino compounds include both amines and diamines, althoughthe diamines disclosed herein are preferred. The useful amines include Calkyl primary amines, C alkenyl primary amine and mixtures thereof.Examples of these include l-aminooctane, laminodecane, l-aminododecane,l-aminotetradecane, l-aminohexadecane, l-a minooctadecane andlaminooctadecene. They are available as mixtures of two, three or moreof these primary amines and are marketed by Armour & Company under thetradename Armeen. The preferred amino compounds are the diaminesincluding N-(C )-alkyl-l ,3- diaminopropane, N(C )-alkenyll ,3-diaminopropane and mixtures thereof. Examples of these useful diaminesinclude the octyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl andoctadecenyl 1,3- diaminopropanes. These products are available asmixtures of four or more of these diamines and sold by Armour & Companyunder the tradename Duomeen." A particularly preferred commercialproduct is Duomeen T which is a mixture of 2 percent of the tetradecyl,24 percent of the hexadecyl, 28 percent of the octadecyl and 46 percentof the octadecenyl, 1,3- diaminopropanes. l find that the mole ratio ofthe reactants can vary between certain limits while still yieldinguseful imideester derivatives of the copolymer. The mole ratio of thecopolymer, i.e., the recurring copolymeric unit, to alcohol to aminocompound should be between about lzlM and l:%:% with a preferred moleratio being about 112%.

In the second reaction step of the process wherein the amino compound isreacted, a catalyst is required to effect the reaction. Useful catalystsinclude the strong organo-inorganic acids such as p-toluenesulfonic acidand benzenesulfonic acid. l-2 wt. percent of catalyst, based on thereactants, will catalize the reactions.

The process is performed and the reaction mechanism is postulated to beas follows: The copolymer is dissolved in a suitable hydrocarbon solventsuch as xylene to which is then added the alcohol. This mixture isheated under refluxing conditions while removing water of formationwhich forms to complete the reaction, with the reaction taking place atthe anhydride functions of the copolymer. A hemi-ester results from thisinitial step, i.e., esters and acids are formed at the anhydride sitesdepending on the ratio of reactants used. The next step involves theaddition of catalyst and the amino compound to the reaction mixture anda continuation of the heating under refluxing conditions with theremoval of water of formation as it forms. in this step the imidefunctions form at some of the acid and ester sites to produce acopolymer derivative havlene. 140 grams of dodeeanol (about 0.75 moles)were added to this mixture and refluxed for four hours while water offormation was removed. Then 3 grams of p-toluenesulfonic acid and 35grams (about 0.125

ing imide and ester functions at what were formerly an- 5 moles) ofDuomeen T were added. This is a tradename hydride sites. of a product ofArmour & Co. and is a mixture of N- it should be understood that sincemixtures of the alalkyl-l,3 diaminopropanes and N-alkenyl-l,3diaminocohols and the amino compounds may be employed propanes. Thealkyl and alkenyl groups are derivatives and a copolymer serves as thebackbone for the anhy- 0f IallOW acids and COIlSiSI inly lG and H4normal dride sites and the reactions will occur randomly on theSaturated hydrocarbon Chains a d m copolymer, the possible compounds andisomers mono-unsaturated Chain$- there f hi h are f d are quite numerousd f. The entire reaction mixture was heated under refluxtentimesdifficult, if not impossible, to catalogue comg conditions Overnightwater f mpletely. However, typical reactions can be postulated lion wasremoved during refluxihg- The Pmduct was d an average or i l compoundcan b d ib d 15 precipitated with 1,500 ml. of methanol, the liquid wasalthough this does not thereby preclude the formation decanted, and theP y was recovered and dried of compounds other than, or isomers of, thatdescribed. Under Vacuum at 25005 Infra-Ted analysis of the P y-Certainly, where mixtures of reactants are employed mer productidentified imide and ester substituents on the possibilities arelimitless. Further, varying the mole the p y ratio of the reactants canchange the number and type EXAMPLE of groups formed on the copolymerbackbone. However it is possible to describe an average" or typical Theadhesive Properties of these derivatives were number of imide and esterfunctions which are found demonstratedper four recurring copolymericunits of the product of A Percent benzene Solution of the copolymer myprocess. This is set forth in Table 1 below for the 25 rlvatlve ofExample l was P p few P of the f l mole ratio range f reactants as we"as the solution were placed between a series of materials and f d moleratio held together at ambient temperature overnight. In all instancesthe materials were overlapped and the contact area was approximately 12inch X 1 inch. NO, SUBSTlTUENT The results are shown in Table ll below.

GROUPS PER FOUR MOLE RATIO OF RECURRING W B AF ANT V A COPOLYMERIC UNITScopolymer Alcohol Airin V "iiir'id" H Ester MATERIALS RESULTS 1 W2 1/4 62 strips of cardboard Stuck fast together l in g 3 Glass strip and brassStuck tightly together, transstrip parent joint 2 aluminum strips Stuckfast together but could These imide-ester derivatives of ethene-maleicanhybe pried apart y hand dride copolymers exhibit properties which makethem 40 2 wooden smps Stuck rm tGamma, but could useful as adhesives andprotective coatings. As an adbe ried apart b hand hesive, thesederivatives will tightly affix both similar 2 steel Smps Stuck fag mamaand could and dissimilar materials to each other. Both porous and not bepried apart by hand non-porous, metal and non-metal materials may be af-2 glass Slides swck fa together and could fixed together. The types ofmaterials which can be adnot be pried apart by hand. hered togetherinclude cardboard, paper, wood, ceraml f clear and "ansparcm ics,plastics, glass and metals, for example, brass, cop- 1mm per, steel andaluminum. The transparent quality of these derivatives makes themparticularly attractive for bonding transparent materials such as glassto each EXAMPLE In other to "Oh-transparent materials These derivativeswere evaluated as protective films.

As a coating, these materials form a thin, continuous transparent filmto protect the surfaces of the metals P i n of brass, aluminum, steeland glass strips and "On-metals listed These films y be were dipped intoa 25 percent benzene solution of the form y ipping the material to beCoated in a SOlllcopolymer derivative of Example I. The strips wereretion of the derivative with a volatile solvent, permitting v d f h l ih excess permitted to d i the excess to drain off and allowing thesolvent to evapoff and the remaining film allowed to dry at roomtemorate. I perature. The strips were then placed in beakers con- Thefollowing exemplify my invention. taining 8 percent hydrochloric acid.In a few minutes EXAMPLE I theuncoated portions of the metal strips werecorroded while all coated portions were unchanged. An imide-esterderivative of an ethene-maleic anhy- I claim: dride linear copolymer wasprepared. 1. A method of protecting metal and non-metal sur- 63 grams(about 0.5 moles) of an ethene-maleic an- 65 faces which comprisesapplying to the surface thereof hydride copolymer having an averagemolecular weight of 15,000 to 20,000 and sold by Monsanto Co. under thetradename DX-840 was dissolved in 500 ml. of xya film of an imide-esterderivative of an ethene-maleic anhydride copolymer prepared by a processwhich comprises:

a. reacting together under refluxing conditions a 1:] linear copolymerof ethene and maleic anhydride having an average molecular weightbetween about 10,000 and 25,000 dissolved in a hydrocarbon solvent andan alcohol selected from the group consisting of C saturated aliphaticalcohols, C unsaturated aliphatic alcohols and mixtures thereof,

b. adding to the reaction mixture of step (a) an amino compound selectedfrom the group consisting of N -(C )alkyll ,3-diam inopropane, N(C)alkenyl- 1,3-diaminopropane, C alkylamine, C alkenylamine and mixturesthereof and a catalyst comprising a strong organoinorganic acid,

0. reacting under refluxing conditions the mixture of step (b),

d. removing water of formation formed in step (c) from the reactionmixture, and

e. recovering from the reaction mixture, an imideester derivative of theethene-maleic anhydride copolymer 2. A method according to claim 1wherein the amino compound of step (b) is selected from the groupconsisting of N(C )alkyl-l ,S-diaminopropane, N-(C)alkenyl-l,3-diaminopropane and mixtures thereof.

3. A method according to claim 1 wherein the copolymer has an averagemolecular weight of between about 15,000 and 20,000, the alcohol isl-dodecanol, the amino compound is a mixture of N(C,., )alkyl-1,3-diaminopropane and N-(C )alkenyl-l ,3- diaminopropane, the solventis xylene and the catalyst in p-toluene sulfonic acid.

4. A method according to claim 1 wherein the mole ratio of the recurringcopolymeric unitzalcoholzamino compound is between about 111 %:'A andl:/:%.

5. A method according to claim 3 wherein the mole ratio of the recurringcopolymeric unitzalcoholzamino compound is about lzlz ro-mso PatentNo,3,810,276 mm ay'l4, 1974 ABRAHAM MORDUCHOWI'I'Z Invmmmrw It 1m amt-fliedthat @rrm: appwm in mm mkmmddemtified patent and that eaifi Letmm Patentmm hamhy wzrmem m mam M1092 F Column 6, Line 13, "in" should read --is-'1 si ned and sealed this 8th day of October 1974.

(SEAL) Attest:

MCCOY M. GIBSON JR. c. MARSHALL DANN Attesting Officer Commissioner ofPatents

2. A method according to claim 1 wherein the amino compound of step (b)is selected from the group consisting ofN-(C8-20)alkyl-1,3-diaminopropane, N-(C8-20)alkenyl-1,3-diaminopropaneand mixtures thereof.
 3. A method according to claim 1 wherein thecopolymer has an average molecular weight of between about 15,000 and20,000, the alcohol is 1-dodecanol, the amino compound is a mixture ofN-(C14-18)alkyl-1,3-diaminopropane andN-(C18)alkenyl-1,3-diaminopropane, the solvent is xylene and thecatalyst in p-toluene sulfonic acid.
 4. A method according to claim 1wherein the mole ratio of the recurring copolymeric unit:alcohol:aminocompound is between about 1:1 1/2 : 1/4 and 1: 1/2 : 3/4 .
 5. A methodaccording to claim 3 wherein the mole ratio of the recurring copolymericunit:alcohol:amino compound is about 1:1: 1/2 .